As is generally well known, one style of cutting tool for use on earth working and land clearing equipment includes a conical pointed working end and an axially extending shank portion for securely mounting such cutting tools within an aperture of a tool holder which is welded to a chain attachment or a rotatable drum of such earth working and land clearing equipment.
Contact of the working end with material to be cleared or removed generally shatters such material and produces small pieces or shredded remnants that can be easily removed or left on the ground surface for natural decomposition. The shank portion of such pointed cutting tool is secured to the support block either with external retaining clips engaging the rear surface of such tool holder or with retaining pins engaging a groove formed within the aperture and a complimentary groove formed in the shank portion. The use of internally disposed retaining pins facilitates ease of replacement of such cutting tool during use. Furthermore, a rotatable attachment of the cutting tool is preferred for extending its life by utilizing the entire cutting surface.
Another style of cutting tool presently used includes a shallow concave cutting surface formed within a working end typically having a larger diameter. U.S. Pat. No. 5,078,219 issued to Morrell et al teaches one type of such concave cutting tool for a non-percussive excavation machine wherein the concave cutting surface is part of an insert which is attached to the shank portion either by mechanical means or by brazing. Additionally, the shank portion is secured to the support block with external retaining clips.
U.S. Pat. No. 5,333,938 issued to Gale illustrates the insert having a concave cutting surface with an axially disposed hollow bearing and which is attached with a fastener extending through such hollow bearing into the support block.
U.S. Pat. No. 5,456,522 issued to Beach teaches a rotatable cutting tool wherein the concave cutting surface is formed by a plurality of carbide inserts brazed to the cutting tool body and wherein the shank portion is secured to the support block with external retaining clips.
It has been found that in applications of clearing land having lush vegetation with small diameter trees and brush and where disturbance of the ground surface is prohibited, the cutting tools with the pointed working end were bending such vegetation and were leaving remnants of six inches and longer sticking from the ground surface. Such situation is undesirable, as it requires additional clearing effort to reuse the land.
The disadvantage of presently available cutting tools with concave cutting surface is an increased cost due to the design of such cutting tools and due to their replacement effort during use.
Therefore, there is a need for an improved cutting tool that is better suitable for economical clearing of lush vegetation in close proximity to the ground surface.